The present invention relates to medical diagnostic ultrasonic imaging systems, and in particular to auxiliary processors for such systems that can be used to expand system resources efficiently.
Modern medical diagnostic ultrasound imaging systems are tightly integrated and highly engineered products. During the life of these products digital processing technology often improves in unforeseen ways. Such technological improvement can obsolete the basic internal resources of the imaging system. For example, modern ultrasound imaging systems include central processing units (CPU's), memory, input/output channels, and operating systems, all of which can quickly become limiting factors. For example, existing CPU's in 1998 are at least 20 times faster than those available in 1993. Memory grows ever less expensive, and the ability of a relatively slow CPU to use large memory effectively is less than that of a newer, faster CPU. State-of-the-art disk interfaces of 1998 provide more than ten times the performance of disk interfaces of 1993. Newer types of disk interfaces may make older ones completely obsolete.
Furthermore, the conventional resources of an ultrasound imaging system provide limited input/output flexibility. Circuit board space and design flexibility are expensive, and it is difficult to justify a spare slot on a proprietary bus for undefined future expansion. Furthermore, it is often not even possible to predict which type of a bus slot should be provided. For example, it was not possible in 1993 to predict that USB or IEEE 1394 Firewire slots would be desirable in 1998.
Furthermore, a conventional, tightly integrated ultrasonic imaging system, including its underlying operating system support, often limit the flexibility to innovate and explore alternatives. Generally speaking, third-party software operating systems and applications are difficult or almost impossible to use with a conventional tightly integrated ultrasound imaging system.
The traditional approach to these problems is to increase the engineering effort to redesign imaging system hardware to improve the CPU memory and I/O performance. This effort can be effective, but it often provides only a partial or temporary solution. Additional engineering effort required for software and operating system enhancement can extend product development cycles to the point where the cost of the engineering effort exceeds the anticipated return on the investment.
One prior-art approach to this problem is the Acuson QV100 system. The QV100 system provides a proprietary serial and two-way video connection between an ultrasound imaging system and a Macintosh computer. The Macintosh computer is programmed to perform image captures and to save the images to an image server. Image transfers are performed via a two-way analog channel from the ultrasound system to additional video frame grabbing hardware on the Macintosh computer. This device is limited to performing only image capture, display, and server functions. Alternate ultrasound applications are not part of this device. The QV100 system simply acts as a frame grabbing and storage system that is added to the conventional ultrasound imaging system capabilities.